Currently, organic light-emitting diode (OLED) display modules have been widely used due to their advantages such as self-illumination, high contrast, thinness, fast response, flexible display, and the like. Generally, after an OLED display module is fabricated, it is required to modulate its brightness under different grayscales according to a target gamma curve to make the brightness under respective grayscales of the OLED display module conform to the target gamma curve, so that an OLED display device can accurately display details of different brightness in an image when displaying the image. Gamma voltage is a data voltage that is set for grayscale display of the OLED display module according to the target gamma curve. The gamma voltage is converted into an analog voltage by a digital-to-analog converter in a data driving chip (source driver), and finally provided to a data signal line in the OLED display device, thereby realizing image display.
At present, as large-sized display screens have been applied more and more widely, the data driving chip of the display module is required to have more output signal channels to meet the requirements on resolution. However, limited by the current manufacturing process for the data driving chip, it may be difficult for a single data driving chip to satisfy large-sized display devices that require a higher resolution. Therefore, in some display devices, two or even more data driving chips are used to drive the display module.